《Chap04.ppt

The Market Forces of Supply and Demand供给与需求的市场力量 Chapter 4 The Market Forces of Supply and Demand Supply and demand are the two words that economists use most often. Supply and demand are the forces that make market economies work. Modern microeconomics is about supply, demand, and market equilibrium. 供给与需求的市场力量 供给和需求是经济学家最常用的两个词。 供给和需求是让市场经济运行的力量。 现代微观经济学就是关于供给、需求和市场均衡的学科。 Markets A market is a group of buyers and sellers of a particular good or service. The terms supply and demand refer to the behavior of people . . . as they interact with one another in markets. 市场 市场 是指某种物品或劳务的一群买者与卖者的集合。 供给与需求这两个术语是指人们在市场上相互交易时的行为。 Markets and competition 市场与竞争 Buyers determine demand. 买者决定需求 A Competitive Market 竞争市场 A competitive market is a market in which there are many buyers and sellers so that each has a negligible impact on the market price 竞争市场——有很多买者和卖者的市场，所以每一个买者或卖者对市场价格的影响都可以忽略不计。 Competition: Perfect and Otherwise Products are the same Numerous buyers and sellers so that each has no influence over price Buyers and Sellers are price takers 竞争: 完全及其它 产品是完全相同的。 买者和卖者如此之多，以至于没有一个买者或卖者可以影响价格。 买者和卖者都是价格接受者。 Competition: Perfect and Otherwise Monopoly One seller, and seller controls price Oligopoly Few sellers Not always aggressive competition 竞争: 完全及其它 垄断 一个卖者，卖者决定价格。 寡头 少数几个卖者。 并不总是主动地进行竞争。 Competition: Perfect and Otherwise 竞争: 完全及其它 Demand 需求 Quantity demanded is the amount of a good that buyers are willing and able to purchase. 需求量是指买者愿意而且能够购买的一种物品或劳务的数量。 Law of Demand 需求规律 The law of demand states that there is an inverse relationship between price and quantity demanded. 需求规律认为，价格与需求量之间的关系是负关系。 Demand Schedule 需求表 The demand schedule is a table that shows the relationship between the price of the good and the quantity demanded. 需求表 —— 表示一种物品的价格与需求量之间关系的表格。 Catherine’s Demand Schedule 凯瑟琳的需求表 Demand Curve 需求曲线 The demand curve is the downward-sloping line relating price to quantity demanded. 需求曲线——把价格与需求量联系在一起的向右下方倾斜的曲线。 Fig